Final answer:
Single-issue, ideological, and splinter parties are types of political parties that exist outside of the two major parties in the United States. Splinter parties are the most short-lived due to factors such as reliance on charismatic leaders and challenges in sustaining party structure.
Step-by-step explanation:
Single-issue, ideological, and splinter parties are all types of political parties that exist outside of the two major parties in the United States. Single-issue parties focus on advocating for a specific cause or set of related causes, such as gun rights or environmentalism. Ideological parties, on the other hand, promote a broader ideology or set of political beliefs, like libertarianism or states' rights. Splinter parties are formed when a faction breaks away from one of the major parties.
While all three types of parties have struggled to gain traction at the national level, splinter parties tend to be the most short-lived. This is because they often rely heavily on the charisma and influence of their leaders. When those leaders are defeated or discredited, the party often loses its core support and collapses. Additionally, splinter parties may face challenges in gaining the resources and infrastructure needed to sustain a viable party structure. Ultimately, many supporters of these parties end up rejoining one of the major parties.